Graphene is two-dimensional monoatomic carbon material formed from sp2-hybridized carbon atoms. Due to its excellent electrical properties, thermal properties, mechanical properties and biological relevance, graphene has been widely applied. Graphene can be used as an ideal nano-filler for preparing composite material. Due to its excellent characteristics, graphene can endow other materials with excellent properties if being composited with these materials. Therefore, graphene composite material has rapidly become a hot topic in the research field of nanocomposite material.
Polyamide, also called nylon, is a collective term of high polymers containing amide groups in repeating units of the macromolecular backbone. Polyamide itself has good overall performance, including mechanical properties, heat resistance, wear resistance, chemical resistance, self-lubricity and the like, and is thus a kind of important high polymer material.
When graphene is used as a reinforced phase of polyamide, due to the large specific surface area and high adhesion between graphene and polyamide, the related properties, such as crystallization properties, thermostability, electrical conductivity, thermal conductivity and mechanical properties, of nylon can be improved by the excellent characteristics of graphene. In this way, the application range of polyamide material is expanded. Therefore, the research on graphene polyamide composite material has attracted more and more attention.
At present, there are following two main methods for preparing graphene/polyamide composite material: melt-blending and in-situ polymerization. In-situ polymerization means that graphene and polyamide monomer are together added to a reactor and then polymerized to obtain the desired composite material. By this method, the problems of dispersion and compatibility of graphene nanoflakes in the polyamide matrix can be solved, and composite material with high dispersibility can be obtained.
However, in the prior art, the in-situ polymerization of graphene and polyamide is realized only in laboratories. It has not yet been used in large-scale industrial production. How to introduce graphene into the existing industrial polyamide polymerization production processes and effectively disperse graphene in polyamide is a problem that must be solved to realize the industrial production of graphene and polyamide composite material.